This invention relates to an oven for treating web stock, especially textile stock in a tentor frame, and more particularly to such having unique flow control of gaseous materials.
In the typical treatment of textile fabric during manufacture thereof, a generally continuous web of fabric is ultimately passed through a tentor frame for stretching and drying of the textile held by tentor hooks or the equivalent along the edges of the web. Heated gases are forced over and through the stretched fabric in substantial volumes for drying. During this process, the temperature of the gases must be limited to a predetermined maximum to avoid damage to the fabric due to overheating during drying or during the post-drying heat treatment. Consequently, it is typically necessary to have several tentor frame dryer sections in series to achieve effective drying and post-drying heat treatment. Such equipment requires substantial capital outlay, space, and heat input. A great share of this generated heat is exhausted to the atmosphere and lost in the volumes of gases discharged. These gases are laden with varying amounts of liquids removed from the fabric during drying. When processing double knit fabrics, such liquids typically include oily compounds deposited on the fabric during the previous knitting operation, solvents, and carriers for the dyes. These are carried by the drying gases, in minute form and often partially combusted, into the atmosphere as smoke and fine mist. This of course is not ecologically desirable. Furthermore, some of the oily substance has a tendency to condense and coat the equipment interior and cause potential problems and fabric damage.
In sum, it is recognized in the trade that present tentor dryer equipment, though effective, is expensive and moreover is space consuming because of the number required. Not only the fabric mills, but also the public in general is encumbered with higher fuel costs and fabric costs due to the tremendous quantities of fuel necessary for the tentor dryers. And the public also has the ecological disadvantage of undesirable stack discharges. Though such discharges are questionable as to meeting governmental guidelines, the mills have not heretofore had available to them tentor dryers that are effective in this regard. The invention herein therefore endeavored to devise and develop an oven system which would cause more efficient and rapid drying and heat treatment of web stock, particularly textile fabric in a tentor, using less fuel and less equipment, and resulting in ecologically improved, controlled stack discharge. This was done by converting an existing tentor to incorporate the new concept. The converted apparatus, set forth in the inventor's copending application Ser. No. 811,583, filed June 30, 1977, and entitled TENTOR, is proving to be a significant advance over the apparatus otherwise used. The inventor then undertook to devise and develop unique apparatus which would replace present equipment.